Structure and Phase Formation in the Ti–Al–Mo–N and Ti–Al–Mo–Ni–N Systems during the Arc PVD Coating Process

— Nanostructured Ti–Al–Mo–N and Ti–Al–Mo–Ni–N coatings with a layered architecture have been grown by arc PVD. We have determined deposition parameters (reaction gas (nitrogen) pressure and negative bias voltage applied to the substrate and determining the energy of incident particles) that enable the formation of a two-phase nitride (TiN + Mo 2 N) coating in the Ti–Al–Mo–N system and a nitride–metal (TiN + Mo 2 N + Ni) coating in the Ti–Al–Mo–Ni–N system. The addition of Ni to the composition of Ti–Al–Mo–N coatings leads to a decrease in the average grain size of the nitride phases from 35 to 12 nm and reduces the modulation period from 50 to 35 nm by limiting the growth of nitride nuclei. This is accompanied by a decrease in biaxial macrostress: from σ = –2.51 GPa in the Ti–Al–Mo–N coating to σ = –0.67 GPa in the Ti–Al–Mo–Ni–N coating.